This invention relates to an air spring having a height adjusting means for keeping constant the compressive deformation (or stroke).
When the treads of wheels of a railroad car are worn, they have to be reground. When they are reground, the car height reduces. With the railroad car having air springs, it is ordinary to increase its height to the original level after regrinding of the treads by interposing a shim between each air spring and the chassis of the car to keep constant the compressive stroke of the air springs to prevent changes in properties due to changes in the stroke.
An air spring proposed in unexamined Japanese patent publication 9-89029 has an upper and a lower face plate having stopper member's opposing each other. Each stopper member has a flat surface and a protrusion protruding toward the opposing stopper member. One of the stopper members is turnable.
With this air spring, the upper limit of the compression stroke when the protrusion of one of the stopper members is opposed to the flat surface of the other stopper member is equal to the upper limit of the compression stroke when said one of the stopper members is turned until the protrusions of both stopper members face each other and the air spring is inflated until its height increases by an amount equal to the height of the protrusions. Thus, by turning the stopper member during car height adjustment with the height of the protrusions of the stopper members adjusted to a value equal to the amount of car height adjustment, it is possible to maintain the same compression stroke after the car height adjustment as before.
In order to raise the entire air spring by interposing a shim, the air spring has to be dismounted from the chassis. This method is thus troublesome.
The two relatively turnable stopper members of the air spring of unexamined Japanese patent publication 9-89029 function as a kind of built-in shims. With this air spring, too, in order to turn one of the stopper members, the air spring has to be dismounted from the chassis. Height adjustment is thus troublesome.
An object of this invention is to solve these problems.